How often can you reuse KN95 or N95 masks — and how do you safely do it? What to know

Health experts have recommended switching to N95 or KN95 face masks as the omicron coronavirus variant — which transmits and evades COVID-19 vaccines more easily than past strains — spreads throughout the United States.

But can these higher-quality masks be used more than once?

Some experts say yes — with limitations — as long as it’s done safely. Here’s what to know:

Reusing N95 and KN95 masks

N95 and KN95 respirators are designed for a single use, so reusing them is not ideal. But some experts say that members of the general public should be able to get away with wearing them a few times before they need to be thrown out, if they take certain steps.

Experts told WWL that storing masks in a paper bag for 24-48 hours between uses is one to way to reuse them.

“The concern about wearing a mask in public, obviously, if you get particles on it, perhaps even the virus, but if you store it in a dry bag, you are essentially sanitizing again over a period of time,” Dr. Joe Gastaldo, an infectious disease expert at OhioHealth, told the outlet.

Dr. Jessica Shepherd, chief medical officer at VeryWell Health, explained the bag isn’t actually sanitizing the mask. The method is about the “process of keeping the mask” from contaminating another person or surface and “keeping a dry environment in order for the virus to not spread or stay on the mask.”

Experts recommend having multiple masks on hand to put them in a rotation.

“For an N95, we’d recommend you switch (the mask) every day,” Dr. Sabrina Assoumou, an infectious disease physician at Boston Medical Center, told USA Today. “But, you can rotate them. If you have three masks, (for example), you could number them and switch them around.”

Dr. Jeremy Biggs, chief of the Division of Occupational and Environmental Health at the University of Utah, said in a blog post that he also recommends rotating KN95 masks and letting them sit for a day before reusing them. He noted that they cannot be washed.

The Navajo Department of Health in Arizona recommends storing one mask per bag and marking who uses it. These bags should be “disposed of or cleaned regularly.” You can also hang the masks in a “designated storage area.”

Health care workers, however, should not reuse respirators.

During a previous shortage of personal protective equipment, or PPE, the Centers for Disease Control and Prevention said health care workers could wear one N95 per day and store it in a breathable bag for at least five days before another use. But as the availability of respirators has increased, the agency said health care facilities should no longer be “using crisis capacity strategies.”

When to toss your N95 or KN95

These masks cannot be reused indefinitely. Eventually, they’ll need to be thrown out as their effectiveness declines over time, experts say.

In the CDC’s recommendations for a shortage of PPE, it said that each time an N95 is removed and put back on, it weakens and stretches the straps, meaning they’ll no longer be able to “generate enough force to create a tight seal with the face.” Therefore, it recommended limiting the number of times a mask is removed and put back on to five.

Experts told USA Today that it’s important to look for signs that you need to throw your N95 or KN95 away: “fraying, stretched out straps or a deterioration of the mask.”

If your mask is “visibly dirty or damaged,” contaminated with “bodily fluids” or used in close contact with someone with an infectious disease, it should be thrown out, the Navajo Department of Health said. You should also throw the respirator out if you accidentally touch the inside of it.

The department also recommends limiting reuses to five.

Any time you put on or remove a mask, the CDC says you should wash your hands immediately. Only handle masks by the ear loops or ties and do not touch the mask while wearing it.

Masks and omicron

Experts largely seem to agree that N95 or KN95 masks are the best option as omicron spreads, especially if in a crowd. Surgical masks may be the next best option, Public Health Insider reported, followed lastly by cloth masks.

“Cloth masks are little more than facial decorations,” Dr. Leana Wen, a public health professor at the Milken Institute School of Public Health at the George Washington University, said on CNN in December. “There’s no place for them in light of omicron.”

Double-masking can also boost your protection if you don’t have access to a KN95 or N95 mask, Dr. Christian Ramers, infectious disease specialist at Family Health Centers of San Diego, told KGTV.

N95 and KN95 masks are not the same. While real N95s are certified by the National Institute for Occupational Safety and Health in the U.S., KN95s are manufactured and approved in China, USA Today reported. KN95s, however, tend to be more widely available to the general public. Both are “rated with 95% filtration efficiency.”

You should be careful when buying respirators, however, as the CDC says many sold in the U.S. are counterfeit.